Drawing instrument



FIG. 1 is a front elevational view of a drawing instrument showing my new design;

FIG. 2 is a rear elevational view;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan view; and

FIG. 5 is a right side elevational view thereof, the left side elevational view being a mirror image. 

The ornamental design for a drawing instrument, as shown and described. 